Retention rate of pregabalin in drug-resistant epilepsy: 1-year follow-up, single-centre observation in 105 consecutive, adult patients

Objectives: Pregabalin (PGB) is a newer antiepileptic drug (AED) licensed as add-on treatment for partial epilepsy in adults. Efficacy and safety have been proven in several controlled clinical studies. These trials, however, only partially reflect clinical practice. Retention rate has been established as a marker for efficacy and safety of AEDs in long-term follow-up studies. Methods: We evaluated the data of the first 105 patients treated with PGB at Bethel Epilepsy Centre, a tertiary referral centre for epilepsy. The patients were interviewed after 3, 6 and 12 months. Results: 105 adult patients (aged 38 ± 13 years) were treated with PGB, on average in combination with 2.1 AEDs (mean observation period 232 days). 76.2% had focal epilepsy, 19.0 multifocal epilepsy, and 3.8% epilepsy with both focal and generalised seizures. 40% continued PGB with the following outcome: 5.7% seizure-free for at least 1 month (4.8% for at least 3 months, 2.4% for at least 6 months; one of the seizure-free patients, however, had had epilepsy surgery during the observational period), 17.1% responders (≥50% reduction of seizure frequency but not seizure-free), 13.3% with unchanged or increased seizure frequency. Reasons for withdrawal were lack of efficacy (47.6%) or side-effects (12.7%). Conclusions: PGB is a new therapeutic option as add-on therapy for patients with highly refractory focal epilepsies although the therapeutic success that can be expected in this group of patients is limited.